Heat-sensitive recording material

Abstract

A heat-sensitive recording material including at least a heat-sensitive recording layer, a light transmittance adjusting layer and a heat resistant protective layer on a support, wherein oxygen permeability of the light transmittance adjusting layer is 0.8 or less, and the light transmittance adjusting layer includes a polyvinyl alcohol having a saponification rate of 90 mol % or more.

1. A heat-sensitive recording material comprising a support having disposed thereon at least a heat-sensitive recording layer, a light transmittance adjusting layer and a heat resistant protective layer,
 wherein the light transmittance adjusting layer includes a polyvinyl alcohol having a saponification rate of 90 mol % or more, and  
 wherein oxygen permeability of the light transmittance adjusting layer is 0.8 or less.  
 
     
     
       2. The heat-sensitive recording material according to  claim 1 , wherein the light transmittance adjusting layer includes at least one selected from the group consisting of a polyvinyl alcohol, a modified polyvinyl alcohol, a styrene-maleic anhydride copolymer, a butadiene-maleic anhydride copolymer, an ethylene-maleic anhydride copolymer, an isobutylene-maleic anhydride copolymer, a polyacryl amide, a poly(styrene sulfonic acid), a polyvinyl pyrrolidone, an ethylene-acrylic acid copolymer, gelatin, a carboxymethyl cellulose, a styrene-butadiene copolymer latex emulsion, a carboxy modified styrene-butadiene copolymer latex emulsion, an acrylonitrile-butadiene copolymer latex emulsion, a mica and pigments. 
     
     
       3. The heat-sensitive recording material according to  claim 1 , wherein a content of the polyvinyl alcohol having a saponification rate of 90 mol % or more is 10% by mass or more of the light transmittance adjusting layer. 
     
     
       4. The heat-sensitive recording material according to  claim 1 , wherein the light transmittance adjusting layer includes a polyvinyl alcohol represented by the following general formula (1): 
                 
 
       wherein l, m and n represent a polymerization molar ratio, l represents a real number from 90 to 99, m represents a real number from 0 to 10 and n represents a real number from 0 to 10 and A, A′ and A″ each represent a C 1  to C 8  alkyl group. 
     
     
       5. The heat-sensitive recording material according to  claim 1 , wherein the light transmittance adjusting layer includes a component that functions as a precursor of an ultraviolet absorbent. 
     
     
       6. The heat-sensitive recording material according to  claim 5 , wherein the component that functions as a precursor of an ultraviolet absorbent is included in the light transmittance adjusting layer by a method selected from the group consisting of solid dispersion, emulsification dispersion, polymer dispersion, latex dispersion and microencapsulation. 
     
     
       7. The heat-sensitive recording material according to  claim 5 , wherein the component that functions as a precursor of an ultraviolet absorbent comprises at least one compound selected from compounds represented by one of the following general formulae (2), (3), (4) and (5): 
                 
 wherein:  
 in the general formulae (2) to (5), m represents 1 or 2;  
 in the general formula (2) and the general formulae (3) to (5) when m=1, A represents —SO 2 —R, —CO—R, —CO 2 —R, —CONH—R, —POR 1 R 2 , —CH 2 R 3  or —SiR 4 R 5 R 6 ;  
 in the general formula (2), when m=2, A represents —SO 2 —R 7 —SO 2 —,—CO—, —COCO—, —COR 7 CO—, —SO 2 — or —SO—;  
 in the general formulae (2), (4) and (5), X represents a hydrogen atom, an alkyl group, an alkoxy group, an aryl group or a halogen atom;  
 in the general formula (3), X represents an alkylene group, —COR 7 CO— or —COR 7 CO 2 —;  
 in the general formulae (2), (3) and (5), W represents a hydrogen atom, an alkyl group, an alkoxy group, an aryl group or a halogen atom;  
 in the general formula (4), W represents —COR 7 CO— or —COR 7 CO 2 —;  
 in the general formulae (2), (3) and (4), Y represents a hydrogen atom, an alkyl group, an alkoxy group, an aryl group or a halogen atom;  
 in the general formula (5), Y represents —COR 7 O—O or —OCOR 7 CO 2 —, —CH 2 CH 2 CO 2 R 7 OCOCH 2 CH 2 —, —CH 2 CH 2 OCOR 7 CO 2 CH 2 CH 2 — or —CH 2 CH 2 CON(R 8 )R 7 N(R 8 )COCH 2 CH 2 —;  
 Z represents a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group;  
 R represents an alkyl group or an aryl group;  
 R 1  and R 2  each represent an alkoxy group, an aryloxy group, an alkyl group or an aryl group;  
 R 3  represents a phenyl group which is substituted with at least one of a nitro group or a methoxy group;  
 R 4 , R 5  and R 6  each represent an alkyl group or an aryl group;  
 R 7  represents an alkylene group or an arylene group; and  
 R 8  represents a hydrogen atom or an alkyl group.  
 
     
     
       8. The heat-sensitive recording material according to  claim 1 , wherein the heat-sensitive recording layer comprises at least one layer including, as main components, a diazonium salt compound, a diazo-base coloring agent containing a coupler which undergoes a coupling reaction with the diazonium salt compound, and a binder. 
     
     
       9. The heat-sensitive recording material according to  claim 1 , wherein the heat-sensitive recording layer comprises a compound represented by the following general formula (A) in an amount of 0.05 g/m 2  or more
   R—SO 3 M  General formula (A)  
 wherein, in the general formula (A), R represents an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a polyoxyethylenearyl group, or a polyoxyethylenealkyl group, and M represents an alkali metal.  
 
     
     
       10. The heat-sensitive recording material according to  claim 9 , wherein the compound represented by general formula (A) is sodium dodecylbenzenesulfonate.